Electric arc lamp



Dec. 1, 1936. M. KCjRTING ET A1. 2,062,419

ELECTRIC ARC LAMP Filed Feb. l, 1935 2 Sheets-Sheet 1 5% M flifomey Dec. 1, 1936. M. KORTING ET AL ELECTRIC ARC LAMP Filed Feb. 1, 1935 2 Sheets-Sheet 2 CARBON .7n veniors: Max K6rfi ng, Felix We y flhoz'ney Patented Dec. 1, 1936 UNITED STATES PATENT OFFICE,

Application February 1, 1935, Serial No. 4,447

In Germany February 1, 1934 9 Claims.

Our invention relates to carbon feeding mechanism for electric arc lamps having rod shaped electrodes, as commonly used in search lights, head lights, projecting apparatus and kindred appliances, wherein the feed of one of the rod shaped electrodes, hereinafter briefly called feeding electrode, is accomplished by a gearing positively operated by a motor in such manner, that the luminous arc or the incandescent crater is automatically kept in proper working condition and at its appropriate place relatively to the reflector of the search light or the condensor-lens of the projecting apparatus concerned.

Our invention relates more especially to carbon feeds, wherein the feeding electrode is intermittently advanced while being rotated. With a carbon feed of this type, known in the art, the carbon is intermittently fed by a feeding mechanism comprising pawls, which while revolving are reciprocatedin the feeding direction and engage the carbon. except during their backward movement, viz. when the pawls are returned into their initial position and release the carbon, over which they slide.

One of the principal objects of this invention is to provide a structurally improved carbon feed of the type set forth, in which the feeding electrode is continuously rotated, namely is kept rotating also-while the feed gear is on its backward stroke.

Another object of the invention is to simplify the manipulations necessary in replacing-while the feed gear works the feeding electrode by a fresh electrode, and also in controlling and readjusting by hand the feed and the accurate position of the feeding electrode relatively to its mate and to the other vital parts of the arc lamp.

Still. other objects willbecome incidentally apparent hereinafter to those skilled in this art.

The nature and scope of the invention are briefly outlined in the appended claims and will be more fullyunderstood from the following specification taken together with the accompanying drawings in which Figs. 1-3 show diagrammatically in a small scale arc-lamps for. search lights and projecting apparatus fitted with an electrode feeding mechanism designed. according to this invention,

Fig. 4 is a side elevation partly in section of an electrodefeeding mechanism designed according to this invention,

Figs. 5-?v are-cross sections taken through the feeding mechanism shown in Fig. 4 on lines VV, VI-VI-, V-IIVII respectively;

Fig. 8 is a side elevation of astructurally modified reciprocating mechanism to beusedin connection with this invention.

The electrode feeding mechanism designed according to this invention essentially consists of 5 the following parts:

(I) Asupport having two upright walls I, I, through apertures of which the rod shaped feed.- ing electrode is to pass in the direction of arrow a, and in which ahollow rotary shaft 3 is journailed;

(II-coupling 2) Means attached to said support and hollow shaft for uniformly revolving said electrode around its axis;

(III) A feed gear attached to and cooperatively associated with said coupling means, for intermittently feeding said. electrode in axial direction, while being rotated, and

(IV) Releasing means under the, control of the operator attached to and cooperatively associated with said feed gear for throwing. the latter out of engagement withthe electrode concerned.

In the embodiment of the invention shown in Figs. 4 and 5 said coupling means comprise: A driving shaft 2i] coupled with a, suitable prime mover (not shown), a secondary shaft 20?, a train of gear wheels 2l2l', 2275 cooperatively interconnecting the said driving shaft, secondary shaft and hollow shaft. 3-; three gripping rollers 24, 24, 24" having sharp circumferential edges for engagement with the feeding electrode 2 and being mounted on said rotary shaft 3, so as to be carried around therewithin a/circular. path; slots longitudinally extending in said shaft, through which the said rollers project, thelatter being so arranged with respect to the feeding electrode, that the latter is free to move in axial direction but is positively rotated jointly. with the said rollers 24, 24', 24",

The trunnions. of. said journalled in slotted cheek to gear wheel 5. and are nectedby springs 25, 25'.

In the embodiment of the invention shown in Figs. 4-5 the feed gearconcernedv consists of a gripping mechanism, which comprises:

Three pawls [4, Ma, Mb, which are slidably fitted in slots l3 of the hollow shaft 3 so asto be carried around thereby in acircular path and to be freeto move relatively in an axial and a a radial direction; actuating means for bodily moving said pawls M, in an axial and a radial direction to said hollow shaft 3; the said actuating means comprise a housing 8 having conigripping rollers. are plates 4, 4" attached resiliently intercon- 2 cal inner walls I6 for cooperation with corresponding conical faces provided on said pawls.

A spring H: for resiliently keeping in engagement said pawls and housing; the latter is slidably mounted on said rotary hollow shaft 3 and is coupled therewith by a pin and slot gear 6, 1 so as to be rotated jointly with said shaft and to be free to be reciprocated relatively thereto in an axial direction.

Means are provided for reciprocating said housing 8 at intervals; said reciprocating means comprise a pin l0 rearwardly projecting from said housing 8; a rotary sleeve ll loosely fitting over said rotary hollow shaft 3 and having a crown cam provided thereon for cooperation with said housing and pin; a spring 9 for resiliently keeping in engagement said housing 8 and sleeve II; and means for rotating said sleeve II in the same direction as housing 8 but at a different ratio of speed.

In the embodiment of the invention shown in Figs. 4, 6, '7 said rotating means comprise a couple of spur gear wheels l223, driven by the auxiliary shaft 20' and having a ratio of gearing slightly larger than that of gear wheels 5-22.

Since housing 8 and the pawls l4 engaging the electrode 2 rotate at a ratio of speed slightly exceeding that of the crown cam the pin 10 will periodically travel up the inclined face of said cam with the result that the housing 8, pawls I4 and electrode 2 are slowly advanced in the feeding direction.

After the pin in has passed the crest of said crown cam the housing 8 is returned in its initial position shown in Fig. 4 by spring 9, thereby incidentally disengaging the pawls H, which in turn cease to firmly grip the electrode 2.

Our experiments have shown that an effective gripping contact of the pawls with the electrode 2 is insured by providing said pawls with triangularly shaped teeth l4, which are one-sidedly shaped, pointing in the feeding direction like those of so-called rip-saws.

In order to enable the operator to conveniently replace the feeding electrode 2 by a fresh one, or to re-set by hand the movable electrode into its proper position, or to stop the feeding motion, while the feeding mechanism works, releasing means are provided, which comprise: a collar l1, co-axially fitted on said sleeve H and being adapted to throw said pawls I4, Ha, Mb out of engagement with their housing 8; and means under the control of the operator for moving said collar to and fro in axial direction; said operating means comprise a grooved flange projecting from said collar II, a yoke l8 engaging said flange and a spring loaded handle l9 attached to said yoke and being slidably fitted in the support I.

Various changes and modifications may be conveniently made in the design and structural details of electrode feeding mechanism of the improved type described above, without substantially departing from the spirit and the salient ideas of our invention.

As diagrammatically indicated in Fig. 8 instead of a rotary sleeve formed with a crown cam at its front face for cooperation with the housing 8 for reciprocating the latter a groove 26 may be formed thereon for cooperation with a spring loaded forked lever 30, pivoted at 21 and engaging said groove; and a rotary cam 28 may be provided for imparting a rocking motion to said lever 30.

What we claim is:--

1. In a carbon feed for electric arc lamps a rod shaped electrode, a feed gear for intermittently feeding the electrode, a rotary coupling for continous rotation of said electrode, while being fed, and means for rotating said coupling, said feed gear comprising a longitudinally movable rotary hollow shaft enclosing said electrode, a gripping mechanism cooperatively associated with said hollow shaft, so as to rotate therewith and be free to be reciprocated in an axial direction relatively to said shaft, and actuating means for engaging and disengaging said gripping mechanism and the electrode.

2. Carbon feed for electric arc lamps having the features outlined in claim 1, in which said gripping mechanism comprises a support, a rotary hollow shaft carried by said support, slots formed longitudinally within said hollow shaft, and a plurality of pawls slidingly fitted within said slots for cooperation with the electrode, said pawls being formed with triangular teeth, which are one-sidedly directed in the feeding direction comparable to those of a rip saw.

3. Carbon feed for electric arc lamps having the features outlined in claim 1, in which said gripping mechanism comprises a support, a rotary hollow shaft carried by said support, slots formed longitudinally within said hollow shaft, and a plurality of pawls slidingly fitted within said slots for cooperation with the electrode,said actuating means comprising a housing cooperatively associated with said rotary hollow shaft so as to be rotated therewith and axially reciprocated thereon, and means for reciprocating said housing, the latter enclosing said pawls and being provided with conical inner walls opposed to corresponding conical faces provided on said pawls, and with a spring for resiliently keeping in engagement said housing and pawls.

4. Carbon feed for electric arc lamps having the features outlined in claim I, in which said gripping mechanism comprises a support, a rotary hollow shaft carried by said support, slots formed longitudinally within said hollow shaft, and a plurality of pawls slidingly fitted within said slots for cooperation with the electrode, said actuating means comprising a housing cooperatively associated with said rotary hollow shaft so as to be rotated therewith and axially reciprocated thereon, and means for reciprocating said housing, the latter enclosing said pawls and being provided with conical inner walls opposed to corresponding conical faces provided on said pawls, and with a spring for resiliently keeping in engagement said housing and pawls,-said reciprocating means comprising a pin rearwardly projecting from said housing, a rotary sleeve loosely fitting over said rotary hollow shaft and being formed with a crown cam for cooperation with said housing and pin, a spring for resiliently keeping in engagement said housing and sleeve, and driving means for revolving said sleeve at a rate of speed different from that of the hollow shaft and housing.

5. Carbon feed for electric arc lamps having the features outlined in claim 1, in which said gripping mechanism comprises a support, a rotary hollow shaft carried by said support, slots formed longitudinally within said hollow shaft, and a plurality of pawls slidingly fitted within said slots for cooperation with the electrode, said actuating means comprising a housing cooperatively associated with said rotary hollow shaft so as to be rotated therewith and axially reciprocated thereon,

and means for reciprocating said housing, the latter enclosing said pawls and being provided with conical inner walls opposed to corresponding conical faces provided on said pawls, and with a spring for resiliently keeping in engagement said housing and pawls,-said reciprocating means comprising a pin rearwardly projecting from saidhousing, a rotary sleeve loose- 1y fitting over said rotary hollow shaft and being formed with a crown cam for cooperation with said housing and pin, a spring for resiliently keeping in engagement said housing and sleeve, and driving means for revolving said sleeve at a rate of speed different from that of the hollow shaft and housing-said driving means comprising a main driving shaft and two sets of gear wheels differing in their ratio of gearing and cooperatively interconnecting said main shaft with the hollow shaft and the said sleeve respectively.

6. Carbon feed for electric arc lamps having the features outlined in claim 1, in which said gripping mechanism comprises a support, a rotary hollow shaft carried by said support, slots formed longitudinally within said hollow shaft, and a plurality of pawls slidingly fitted Within said slots for cooperation with the electrode-said actuating means comprising a housing cooperatively associated with said rotary hollow shaft so as to be rotated therewith and axially recipro cated thereon, and means for reciprocating said housing, the latter enclosing said pawls and being provided with conical inner walls opposed to corresponding conical faces provided on said pawls, and with a spring for resiliently keeping in engagement said housing and pawls,-said reciprocating means comprising a groove circumferentially formed on said housing, a spring loaded forked lever, engaging said groove, and a rotary cam engaging said lever and being adapted to impart a rocking motion to the latter at intervals.

7. Carbon feed for electric arc lamps having the features outlined in claim 1, in which said gripping mechanism comprises a support, a rotary hollow shaft carried by said support and having slots longitudinally formed therein, a plurality of pawls slidingly fitted within said slots for cooperation with the electrode, and releasing means under the operators control for throwing said gripping mechanism into and out of operation.

8. Carbon feed for electric arc lamps having the features outlined in claim 1, in which said gripping mechanism comprises a support, a rotary hollow shaft carried by said support and having slots longitudinally formed therein, a plurality of pawls slidingly fitted within said slots for cooperation with the electrode, and releasing means under the operators control for throwing said gripping mechanism into and out of operation,- said releasing means comprising a collar concentrically enclosing said rotary shaft and manually moved to and fro so as to throw said pawls into and out of engagement with the electrode, and operating means for moving said collar in axial direction.

9. Carbon feed for electric arc lamps having the features outlined in claim 1, in which said gripping mechanism comprises a support, a rotary hollow shaft carried by said support and having slots longitudinally formed therein, a plurality of pawls slidingly fitted within said slots for cooperation with the electrode, and releasing means under the operators control for throwing said gripping mechanism into and out of operation, said releasing means comprising a collar concentrically enclosing said rotary shaft and manually moved to and fro so as to throw said pawls into and out of engagement with the electrode, and operating means for moving said collar in axial direction, said operating means comprising a grooved flange attached to said collar, a yoke engaging said flange, and a spring loaded handle attached to said yoke.

MAX KCRTING. FELIX WERNER. 

